Counter-pressure valve.



R. WOOD.

COUNTER PRESSURE VALVE.

APPLICATION FILED MAY 20. 1915.

.- Patented Mar. 21,1916.

l Inventor:

THE COLUMBIA PLANOGRAPH $0., WASHINGTONfD. c.

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ROBERT WOOD, 0F BROOKLYN, NEW YORK, ASSI GNOBI TO THE NATHAN MANUFAC- TUBING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

COUNTER-PRESSURE VALVE.

Application filed May 20, 1815.

under conditions where the control must be frequently exercised and the valve opened and shut manv times to accomplish this purpose. A good example of the intended purpose is the steam starting valveon a locomotive where it is necessary to open and shut the valve frequently against a high pressure of steam; F or such use, I have invented a valve wherein the steam pressure assists in holding the valve upon its seat and at the same, time exerts a counter pressure against the valve so that it can be manipulated without anunusual or undue exertion, and the novelty of the device consists in the construct on of the parts and the means employed to secure the proper performance of the stated function.

In the drawing, there is illustrated a central longitudinal section of a valve and related parts embodying the invention. No other view is presented, because, asmost of the parts are circular or tubular, a sectional view suffic ently displays the construction.

In the drawing, 10 is a valve casing provided on each side with a tubular extension 11 externally threaded to provide means for connecting it tothe conduit through which the steam passes and which it controls. Arranged completely across the casing is a web or diaphragm 12 having a central opening indicated at 13 .surroundedby an annular seat 14, and which casing is provided also with an inwardly extending annular flange 15.

A bonnet 16 having an extending neck 17 externally threaded as indicated at 18 is secured to the casing by any suitable means as the screws 19. A valve stem 20 extends through the bonnet and is loosely connected at its lower end by meansof a transverse pin 21 with a valve disk 22 having an upwardly extending annular flange 23. At its upper end the stem is connected by a pivot 24 to a lever handle 25 pivoted at 26 to a Specification of Letters Patent.

Patented Mar. 21, 1913.

Serial No. 29,318.

link 27 pivoted in turn at 28 to a ring 29 embracing the bonnet 16 and secured tightly against a shoulder30 thereon by means of a retaining collar 31 engaging the threads 18. A stuiiing box of usual form generally indicated at 32 is secured to the bonnet neck 17 and packs the valve stem against leakage.

The valve proper comprises a disk 40 having a seating surface 41 cooperating with the seat 14. Below this is a piston 42 slidably engaging the flange 15 and connecting the disk and piston is a tubular member 43 having a side port 4-4. Above the disk 40 is an annular extension 45 of smaller external diameter than the internal diameter of the bonnet so that there is an annular passageway 46 between them, and of greater internal diameter than the disk 22 so that there is an annular passageway 47 between them. Threaded into the upper part of the extension 45 is an annular plug 48 between which and the valve stem is a passageway 49 and below which is a chamber 50 formed inside of the extension 45 and in which the disk 22 with its flange 23 has a limited vertical movement when the valve stem is reciprocated.

It will be noted that in the described construction there are shown in reality two valves, viz., a primary valve which is made in the form of a cage consisting of the disk 40, the upwardly extending annular flange 45 and plug 48 and which cage is connected by the tubular stem 43 to the piston 42; and a secondary valve 22 which moves inside of this cage and controls the passage of steam from the inlet side of the main valve down into the stem 43 and thence to the lower side of .the piston 42, this valve acting upon a seat formed in the upper side of the disk 40 around the upper edge of the tube 43. Also that there is a leaking port 44 in such passage. Also that the pin 21 forms a loose or hinged connection between the valve stem 20 and secondary valve 22 so as to allow the valve to move properly even if the parts are somewhat out of line.

The operation of the device is as follows: Assuming that steam is comin into the device from right to left, it will press upon the annular edge of the valve disk 40 and help to hold its edge 41 against the valve seat 14; it will also pass up into the bonnet and down around .the valve stem 20 and into chamber 50 and pressing on the upper edge of the flange 23 will help to hold the valve disk 22 down upon the seat formed on the upper side of the disk 40 and shut it out from the passage into the interior of the tube 43. Thus it will be seen the primary and seccndary valves are both held closed by the steam pressure itself.

When it is desired to open the valve, the lever handle 25 is operated and the valve stem raised. This is not difficult to do because the area of the disk 22 is not very great, and the moment that it is lifted from 7 its seat on the upper surface of the disk 40,

the steam which is always present in' the chamber 50passes into the tubular stem 43 and into the space beneath the piston 42 and helps by its pressure thereon to balance the pressure ofthe surface 41 against the surface 14, and by the time the movement of the stem '20 has brought the upper edge of the flange 23 against the lower edge of the plug 48, which limits such movement,

the counter pressure is such that the valve 40 is readily ralsed as the continued movement of the lever handle lifts the plug 48 and with it the remainder of the cage comprising the flange 45 and parts beneath.

The movement of the handle 25 in its opening operation should be gradual, so as to allow a sufficient interval of time between the unseating of the auxiliary valve from its lower valve seat, to the seating of the same against the plug 48, thereby allowing a sufficient amount of fluid to pass to the underside of the piston 42.

IVhen it is desired'to close the valve the handle 25 is moved to lower the stem 20, this moves the secondary valve downward and closing the passageway in the stem 43,

shuts off the steam acting upon the lower part of the piston 42. As soon as this is accomplished the valve 40 practically closes itself by the pressure upon its upper edge. It will be seen therefore that the primary valve is not completely balanced. In fact, its efiiciency depends upon the fact that it is not, but the moment the secondary valve is opened, the primary valve becomes balanced, at least to an extent sufiicient to render its manual operation easy thereafter.

Copies'of this patent may be obtained for The port 44 is provided in case the secondary. valve should leak. In such case,

the steam coming down the stem 43 would naturally pass out throughthis port, and would not exert a counter pressure upon the piston 42. This port 44 is in direct com-V munieation at all times with the chamber or space beneath the piston 42 so that in the closing movement of the valve the steam in the space is allowed to escape, thereby destroying the counter pressure therein.

I claim:

1. In a device of the character described, comprising a valve casing, a valve-seat therein, a valve for said seat, a piston connected to the lower side of the valve and a tubular extension on the upper side of, the

valve, said extension being provided with two valveseats, a' cylinder in which said piston is adapted to reciprocate, a passageway connecting said tubular extension with the chamber in said piston cylinder, a valve in said extension arranged between the seats and adapted to close said passageway when moved to its limit ofmovement in either direction and'to permit fluid to 1 flow to said piston chamber While in its intermediate position. V

2. In a devlce of the character described, compr sing a valve casing, a valve seat therein, a valve for said seat,a piston con- 7 nected to the lower side of the valve and a tubular extension onthe upper side of the itness MARY H; LEWIS.

Washington, D. G.

ROBERTWOOD.

five cents each, by addressing the Commissioner of Patents, 7 

